Symbolic factorization analysis.
count = SYMBFACT(A) returns the vector of row counts for the upper
triangular Cholesky factor of a symmetric matrix whose upper triangle
is that of A, assuming no cancellation during the factorization.
This routine should be much faster than chol(A).
count = SYMBFACT(A,'col') analyzes A'*A (without forming it explicitly).
count = SYMBFACT(A,'sym') is the same as p = symbfact(A).
There are several optional return values:
[count,h,parent,post,R] = symbfact(...) also returns
the height of the elimination tree,
the elimination tree itself,
a postordering permutation of the elimination tree,
and a 0-1 matrix R whose structure is that of chol(A).
See also CHOL2E9HJXR, ETREE , TREELAYOUT .